On a couple of occasions I have opened Arcmap Pro, loaded one of the base maps and used a feature class to digitise an area. When I have printed the maps the base map and my feature class have shifted out of alignment (up to 10m).
I am very careful to make sure that the map is set to British National Grid before starting to digitise the area.
I think this is a transformation issue, as when I open the feature class in Arcmap 10.3.1 it is in the wrong (shifted) position, but I cant work out what I am doing wrong in Arcmap Pro.
Has anyone else experienced something like this?